The present invention relates to a transfer material and a transfer product both of which are so excellent in light resistance as to be less likely to yield fading or discoloration even if exposed to ultraviolet rays. More specifically, the present invention relates to a transfer material which is used in forming an outer layer of articles exposed to ultraviolet rays, and a transfer product having a transfer layer of the transfer material. There are as examples of such articles, sports equipment such as fishing goods, electric appliances such as interphones or personal radio-cassette recorders, and automobile inner and outer decorating goods such as air conditioner control panel, wheel covers, center posts, moldings, bumpers, and taillights.
As a method for decorating articles, which are the target of transfer, transfer process has been available. The transfer process is a process that uses a transfer material in which transfer layers such as a release layer, an expression layer, and an adhesive layer have sequentially been formed on a substrate sheet, and that permits decoration to be accomplished by transferring the transfer layers onto the surface of the transfer-target article. As another method for implementing the transfer process more rationally with a transfer-target article composed of a resin mold, concurrent molding-and-transferring process has been available. The concurrent molding-and-transferring process is a process in which, with resin injected and filled into a molding die having a transfer material sandwiched therein, decorating executed by heat pressure due to molding concurrently with the molding of a resin molded product.
For the purpose of imparting a light resistance property to the transfer material, it has been a conventional practice to dissolve an ultraviolet absorbing agent into a release layer or to provide an ultraviolet absorbing layer, which is composed of acrylic resin and an ultraviolet absorbing agent dissolved therein, between the release layer and the pattern layer. As the ultraviolet absorbing agent, benzophenone base or benzotriazole base low-molecular compounds have been used.
However, the conventionally used ultraviolet absorbing agents would be low in the solubility into resin such that the amount to which they can be dissolved into a resin layer such as the release layer or the ultraviolet absorbing layer would be as small as 10% by weight or under. Accordingly, conventional transfer materials have been such that they do not have enough light resistance because a thin film of around the level for use as a transfer material has a low ultraviolet absorption rate of the release layer or the ultraviolet absorbing layer.
The conventionally used ultraviolet absorbing agents would also be poor in compatibility with resin because of their being low-molecular compounds. Accordingly, the conventional transfer materials would incur such problems as variations in the ultraviolet absorption rate or the occurrence of layer separations because the ultraviolet absorbing agent would bleed from within the release layer or the ultraviolet absorbing layer with time so as to be dissipated or eluted into the other layers or molded product.
Furthermore, the conventionally used ultraviolet absorbing agents would lack in heat resistance because they are low-molecular compounds. Accordingly, with the conventional transfer materials, there would be some cases where the ultraviolet absorbing agent in the release layer or the ultraviolet absorbing layer may be volatilized or decomposed by the heating during a transfer process or resin molding process such that the release layer or the ultraviolet absorbing layer may lose the ultraviolet absorbing function.